Explore the properties of inscribed angles by following these steps.

✓ 1. Move point C so the measure of the inscribed angle ABC is 50°.
What is the measure of arc AC?
°

✓ 2. Move point C so the measure of arc AC is 50°.
What is the measure of ∠ABC?
°

✓ 3. Make a conjecture. Which measures will change if you move vertex B of the inscribed angle? angle ABC arc AC both neither

✓ 4. Move vertex B and observe what happens to the angle measures.
Was your conjecture correct? yes no

✓ 5. What is the relationship between inscribed angle ABC and arc AC?
#&m \overset{\frown}{\sf AC}#& = 1/2 1 2 × m∠ABC